I defined variables which show current component and current system. They can be used by IDEs to navigate to sources, or by your code to do what you need.
I suggested this as a modification of asdf, but asdf maintainers said that special variables are dangerous. Maybe.
My code is here: https://bitbucket.org/budden/budden-tools/src/default/asdf-3.1.4-tools.lisp?...